Surface roughness and optical characteristics evaluations after chairside adjustment of different zirconia types.

STATEMENT OF PROBLEM: Limited evidence is available for the effect of chairside adjustment using rotary cutting instruments on the surface roughness and optical properties of different zirconia types. PURPOSE: To evaluate the effect of simulated adjustments on surface roughness and optical properties of different zirconia types. MATERIALS AND METHODS: Three Partially Stabilized Zirconia (PSZ) types based on mole percent yttria (Y) concentration from the same manufacturer (Katana; Kuraray) were used: 3Y-PSZ, 4Y-PSZ, and 5Y-PSZ. Thirty disk-shaped specimens (Ø14 × 1.2 mm) from different zirconia types (N = 90) were prepared. Specimens were either left without adjustment (NA), adjusted with Dialite ZR finishing and polishing system (Brasseler) (APol), or adjusted with course diamond instruments only (ADia). The specimens were distributed into 9 groups (n = 10): Group 3Y-PSZ/NA, Group 3Y-PSZ/APol, Group 3Y-PSZ/ADia, Group 4Y-PSZ/NA, Group 4Y-PSZ/APol, Group 4Y-PSZ/ADia, Group 5Y-PSZ/NA, Group 5Y-PSZ/APol, and Group 5Y-PSZ/ADia. The surface roughness of specimen was analyzed using an Atomic Force Microscope (AFM) (Bruker's Dimension Icon, Bruker) and Root Means Square (RMS) were recorded (nm). Surface Gloss (SG), Translucency Parameter (TP), and Contrast Ratio (CR) values of all groups were recorded using an integrating sphere spectrophotometer. Statistical analysis was performed using analysis of variance (ANOVA) and Tukey's multiple comparison tests for pairwise comparisons at p < 0.05 and 95% confidence interval. RESULTS: APol had no effect on the surface roughness (p = 0.88) while ADia had a significant negative effect (p < 0.05) despite the type of zirconia. Out of the three testes optical properties, only SG was negatively affected by ADia for all types of zirconia (p < 0.05). The two adjustment types did not affect the TP of all the tested zirconia (p = 0.91). The CR was not affected by the tested adjustments for all zirconia types (p = 0.726). CONCLUSION: Proper zirconia adjustment following a sequence of burs and polishers can maintain acceptable roughness and optical properties. Adjustment of zirconia with rough diamond can lead to deleterious effects and should be avoided. CLINICAL SIGNIFICANCE: Chairside adjustment of zirconia could lead to rougher surface and unpredictable changes of surface gloss. Therefore, zirconia adjustment should be minimized to the greatest extent possible and a proper protocol should be followed if had to be done.

Zirconia restoration types, properties, tooth preparation design, and bonding. A narrative review.

OBJECTIVE: The purpose of this review was to provide dental professionals with information regarding the various types of zirconia restorations, their mechanical and optical properties, tooth preparation design, and bonding protocol in an effort to enhance the longevity and durability of zirconia restorations. OVERVIEW: The yttria content of zirconia ceramics determines their classification. The mechanical and optical properties of each type are discussed, with an emphasis on the effect of yttria concentration on the properties of zirconia. The processing and sintering methods are also discussed as they have a direct impact on the properties of zirconia. The design of tooth preparation, specifically occlusal reduction, varies depending on the type of zirconia used in each case. Finally, a protocol for zirconia restoration bonding is described to ensure optimal bonding to the tooth structure. CONCLUSION: Not all zirconia restorations are the same. The selection of zirconia type based on yttria concentration, processing and sintering methods, tooth preparation design, and adherence to the bonding protocol are all critical to the success and longevity of zirconia restorations. CLINICAL SIGNIFICANCE: Zirconia restorations are the most commonly used indirect restorative material. The selection of the most appropriate zirconia type based on its yttria content, which determines its strength and translucency, is critical to the success and the longevity of the restoration. Tooth preparation design also influences the strength and translucency of the zirconia. Air-borne particle abrasion, followed by a ceramic primer and resin cement, can ensure a durable bond to the tooth structure.

Spectral characterization and biological evaluation of biomolecules from the peels of three orange fruits: a comparative study.

The present work was designed to investigate the presence of bioactive chemicals in the reaction mixtures (RMs) of peels of Valencia, Mandarin, and African navel oranges, through GC-MS and FT-IR studies. Limonene, a unique compound, is present in the RMs of the three orange peels. Moreover, hexadecanoic acid 2-hydroxy-1-(hydroxymethyl) ethyl ester was identified in the RMs of all the three-orange peels. The RM of Mandarin orange exhibited potent cytotoxic effect against MCF-7 ATCC human breast cancer cells (HBC). All the three RMs exhibited moderate antibacterial activity against the human pathogenic bacteria Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 12228), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 700603), Salmonella choleraesis (ATCC 10708), Pseudomonas aeruginosa (ATCC 27853), and Proteus mirabilis (ATCC 299).

Sealing ability in vitro study and biocompatibility in vivo animal study of different bioceramic based sealers.

INTRODUCTION: The effectiveness of root canal therapy in endodontic practice is largely determined by providing a compact fluid-tight closure at the apex of the root canal, which inhibits irritant entry and buildup, which leads to a biological breakdown of the attachment mechanism and failure. During obturation, along with gutta-percha, root canal sealers are employed to fill voids and seal root canals. Root canal sealers come in a variety of shapes and sizes, each with its own set. AIM: Evaluation of sealing ability in vitro study by using scanning electron microscopy (SEM) and biocompatibility in vivo animals study of BioRoot RCS and meta Biomed bio_ceramic sealer (CeraSeal RCS) and compared the findings with that of Zinc oxide eugenol (ZOE) sealer as control. MATERIALS AND METHODS: This study utilized two bio_ceramic sealers (BioRoot RCS and meta Biomed bio_ceramic sealer (CeraSeal RCS) and compared the findings with that of ZOE sealer as control. Biocompatibility was determined by examining histopathological biopsy specimens collected from rabbits. Each rabbit had four dentin tubes implanted into the subcutaneous tissues, one for BioRoot RCS, one for CeraSeal RCS, and one for ZOE RCS, with the fourth tube being empty haematoxylin and eosin were used to stain histological sections, and a light microscope was used to evaluate them. Extracted human single canal premolars were used to evaluate the sealing ability. The root canals were divided into three sections (coronal, middle, and apical). SEM was used to assess the adhesion quality at the sealer-dentin interface. RESULTS: BioRoot and CeraSeal sealers have excellent sealing adaptation and biocompatibility, as well as rapid tissue recovery, while ZOE sealers have a slower recovery of inflammatory reaction results when compared to bio_root and ceraSeal sealers, as well as a less sealing adaptation than the two other bio_ceramic sealers. CONCLUSION: In general, the two bioceramic sealers tested were biocompatible and capable of sealing or adhesion. While ZOE had less adherence ability and less biocompatibility.

Optical properties of bisacryl-, composite-, ceramic- resin restorative materials: An aging simulation study.

OBJECTIVE: Compare optical properties of a bisacryl-, composite-, and ceramic-resin restorative materials pre and post artificial aging. METHODS: Bisacryl-resin (LuxaCrown [LC], DMG), resin-composite (Filtek Supreme Ultra, [Filtek SU] 3M ESPE), and ceramic-resin (Enamic, VITA Zahnfabrik) specimens were prepared. The L*, C*ab , and hab values were measured pre and post artificial aging to determine color stability (CIEDE2000) and changes in contrast ratio (CR), transmittance block, and relative translucency parameter. The datasets were analyzed using 2-way ANOVA followed by pairwise comparisons. RESULTS: Color difference data showed a significant interaction between materials and treatments [F(6:60) = 375.04, P < .0001] with Enamic being most color stable material and coffee having most effect on color stability. CR data showed a significant interaction between materials and treatments [F(6:60) = 4.12, P = .0016]. LC showing most change in CR values with coffee treatment. Change in transmittance blocked by Filtek SU and LC was greater for coffee treatment than that by each of the other treatments (P < .0001). Filtek SU and LC, coffee produced a greater decrease in relative translucency than that each of the other treatments (P < .0001). CONCLUSIONS: Resin-based materials demonstrate optical properties that encourage their use for direct/indirect restorative options. Color stability and translucency of these materials are proportionally related. CLINICAL SIGNIFICANCE: Understanding the optical properties of resin-based materials provides help in material selection and provides insight into clinical performance and esthetic longevity. The optical stability of certain bisacryl-resin is better than what was previously determined for these restorative materials.

Color and translucency stability of contemporary resin-based restorative materials.

OBJECTIVE: To determine color and translucency stability of present-day resin-based restorative materials. MATERIALS AND METHODS: Disk-shaped (1.0 × 10 mm) resin composites (Filtek Universal, 3M ESPE; Spectra ST, Dentsply Sirona; Gradia Direct X, GC America; Estilite Quick, Tokuyama; Harmonize, Kerr; ACTIVA Bioactive-Restorative, Pulpdent) were prepared and divided into four staining groups (n = 5); coffee (55°C), grape juice (5°C), deionized water (25°C) and thermocycling (20 000 cycles, 5°C to 55°C with a 30-second dwell time). Spectrophotometer measurements were taken at baseline and 14 days for each group and the color stability (CIEDE2000) and changes in the translucency parameter (RTPCIEDE2000 ) and luminous transmittance of each composite were determined. A 2-way analysis of variance (ANOVA) using maximum likelihood estimations was used for analysis for these changes, with subsequent pairwise comparisons using Bonferroni-corrected Student's t tests and an experiment-wise α = 0.05. RESULTS: A significant interaction (P < .0001) between material and treatment was found for each change in the esthetic property tested over 14 days. Multiple significant differences between materials for each treatment and between treatments for each material were identified. CONCLUSIONS: The severity of color change and translucency of resin-based materials are dependent on their type, mostly affected by the coffee staining medium. Nano-filled resin composite is most resistant to color change and with stable translucency after artificial aging. CLINICAL RELEVANCE: Nano-filled resin composite may be the most esthetically durable resin- based restorative material. Micro-hybrid resin composite and resin-modified glass ionomer restorative material are susceptible to color change and losing their translucency. Hot coffee solution may shorten the esthetic lifespan of a resin-based material.